Screening ball mill



Nov. 1s, 1924. i 1,516,461 J. -HERMAN SCREENING BALL MILL Filed Jan. 7.1924 2 Sheets- Sheet l ll fl J. HERMAN SCREENING BALL MILL Nov, 18,1924.

. 1924 2 Sheets-Sheet 2 Filed Jan. 7

umnu

Patented Nov. 18, 1924.

PATENT oi-ifflcl..`v

Y JOHN OF LOS ANGELES, CALIFORNIA.

SCREENING BALI. MILL;

, Appiication ma'kraynuary 7,1924. seriaixafersgsoa.

Be it known tha I, ,J y EN HERMAN, a citizen of the United States,residingxfat Los Angeles, in the county fof Los Angeles and a novel andadvantageous mill of the. general type', disclosed inI mypriorPatcnt1,1'(6,896

granted March 28, 1916, .although themill upon which protection isherein soughtI does not comprise bars of the specific-cross-.sectional-'configuration disclosed .in `my mentioned patent (thearea betweenthe bars .continuously decreasing 'in cross-section4 Ksuitably transformed rail sections to a base from the` inside) Among theobjects-and advantages of my novel construction herein presented, I

ma mention not only'aii economy ofma-. ferial, which may result'from anadvantageous vuse of selected sections i of secondhand special steelvrails, or their equivalent,

pulverizing andk screening elements o my novel mill as to secure asuperior dra ging L progressive. although vdiscontinuous v outediminished by the contactof the bases 'of-v ward diminution inthesucce'ssive sizes of the aperturesfthrough which material may beoutwardly delivered `from the same, I

may retain all of the advantages of myl prior construction referred toand at the samer time gain-an eiiciency" of action not obtainablethereby. v

It is a furthereobject of this invention to providel a screening ballmill in which thev openings through lwhich material may;y be

delivered shall be progressively diminishing e in size but in which theeffective screening area of abase screen shall not be unduly bars orrail sections therewith; and aprelferred embodiment of my invention maycomprise rail sections whose bases are se# cured against or inproximityto a base screen in suchv manner as to permit an outwardmovement of material under upturned ,n

or suitably spaced flanges, which ma be formed by a suitable inward oruwa. de- Election of the bases of select` .to above. l but also the factthat by so constructin the A.

sections .of secondhand manganese or otherfspecial steel rails; yandwhen If employ, instead of` said rail sections, bars ofA rectan ularcross-section, I may so position ,the atter also thattheir ,surfaces inproximitysto a basescreen shallbe inwardly and upwardly divergent'therefrom. y v Other objects of my invention will appear yfrom vthefollowing. descriptionv of se ected .their equivalent.

. Fi z 2 is an enlarged .detail 'viewcoi'respon ing thereto.

y VFigg `is\a longitudinal sectional view showing a preferred manner ofsecuring screen, as. hereinafter vreferred to. i 4 is a view correspondibut s owing. a proposed use ofnars which may square in cross-section,altho h so ,positioned'as to gain advantages re erred toy Fig. 1

n Fig. 5 isa detailor fragmentary. perspective `'view showin anorganization of the general character illustrated in Fi 3.

Fi and 7 are perspective an lon 'tudina views showings. :possible lmethof ,settingv rectangular bars of the character last referred to in theend plates'of a screeningz ball v y eferring tothe details of thatspecific embodiment of 11iy invention shown in Figs.-A

1 and 2, l may the substantiall circular rend lates of a mill, these endbeing" pre erably integral withy hollgw trun- `nions 2 through one of-which suitably .subdivided material ma be fed, an outward screeningdelivery being eiected in a known manner, and the product being caughtand collected` in any suitable way, as by means ofv a hopper3eonventiona1ly shown.A l f Instead of employing bars vsubstantially trazoidal in cross-sectional outline, as described and claimed'in mymentionedk rior patent, I propose to employ, in the em iment of myinvention shown in Figs.y 1 and 2, sections of secondhand rails, ortheir equivalent, these being preferably selected .sections of man aneseor otherspecial steel rails which are o tainable at a comparative] A lowcost, although the cold-rolling .to whic they may have kbeen sbjectednin their animatie trans- Y thev samemay referred to previous use may bedistinctly advantageous as contributing to theirl durability Vin a ballmill; and I propose, when I employ rail sections of the-characterreferred Ito, not only to space them apart in a manner Vfavorable to theoutward delivery ofsuit-A ably pulverized material between the basesthereof, but also, as by upsetting or deforming said bases in the mannerbestshown in Fig.V 2 or by equivalent means,-to ,avoid an undue coveringof a base screen to which (which may optionally be formed, inthev caseof a mill having aftransverse diameter of six feet, more or less, of 1/1 inch material providedwith longitudinalrows 'of apertures f6, whosediameter maybe 'approximately 1/2 inchthese dimensions vbeingsuggestedv` by way of illustration and not `by'wayv `of limitationyQ-'toend plates 1,'in a usual or;v preferredmanner, as by riveting through anoutwardly vturned flange -upon `Asaid end plates; and I may support therail sections 6,l or their equivalent, wholly or entirely from thementioned base screen; When the construction last referred to isemployed," I consider it advantageous vto Vdefiect'fthe bases of-*therail sections 6, bending mtermediate portions thereof upwardly andinwardl in such manner as substantially ,i to diminish the area of theircontact with said base screen, although I may optionally re-` tain,between the upwardly deflected sections 7 of the base 8 of a rail 6,un'deflected for substantially fiat areas 9 adaptedto re ceive rivets 10extendingtherethrough andv through said base'screen; and it is of-im.

portancethat the rails '6 shall' be so'spaced throu hout thecircumferenceofa shell or s lcylin er provided therewith that the inter-4 vals between the heads 9 of a pairof lsubstantially parallel rails 6shalliexceed the v"interval between a pair of'upturned flanges 7, andv'that the elements referred to should beused-in conjunction with'balls'andl materials of such size as to be capable toffree lateral lmovementbetween the headsy 9, al-y thoughthe diameter of the mentioned ballsshould exceedv the distance between the f `flanges 7 and the'intervalsbetween thesaid' upwardly deiiected iianges should'be not less than`twice the perpendiculardistance vthereof from the base screen 5, whosevapertures 10 should either beinwardly expanded or of a uniforindiameterless thanthe distancebetween the upturfned anges 7 andv greater than.the mesh of the outer screen 11,

`myinvention shown in Figs. 4 to 7 inclusive,

shown as in contact with said base screen. Referring to the specificembodiment of it will .be obvious that lthe'relationshipsbetweenftheparts herein referred to may be substantially the same as have beendescribed above, inr the' sense that the distances `bebe secured.l Forthe'purposes may secure a' base screen 5 .'twe'enthe llateral edges 12ofthe bars '13 may be substantially greaterthan the diameter of theopenings -14 in the base plate 15 and such as to permita free movementof balls and subdivided material either inwardly or outwardly in aradiall direction therebetween, the mesh of the wire screen 16, shown asincontact Awith'the outer surface of the base screen 15 being, moreover,preferably such that the successive diameters of the yapertures throughwhich material may pass outwardly are progressively, although *notcontinuously, dimlnishing.- `The configuration of the bars 13isadvantageousnot'only in causing drag of material'therewith'l but inpermitting a comparatively freeaccess of nely subdivided material tothebase screen v 15, through whichl it may Vpromptly find enit, if.'capable of passing valso through the '.wirel screen 16, or from which"it may'freely returninto a osition suitable forV further lcomminution,1n case it has not-been suiiiciently ground.. v

Instead of securing thebars 13, or their equivalent, directly toaipsocketxplate rigidly connected with'the end plate 1,orits,equivalent, I may optionally j rovide this"v end'fplate l -not onlywith a `ollow trun-l nion 2- but also with rectangular seats'17cooperating with a' flange 18'invthel retentio'n'of the ends 19 of saidbars, these'ends beings'hown asY halved Aaway in a manner permittingthemto overlap the flange 18 and to bev secured thereto ink anysuitableWay, as vby means of bolts or rivets.

20, shown' as extending also through the base screen 16an'd'maintainingall of the mentioned parts in their intended relationships.

By either of the constructions abovezde-' scribed it kwill beobvious-that 'I have provided a construction Vcomprising rails orv ouslydecreasing in cross-section, as required by said prior patent, they areprogressively the openings in the base screens employed is vlessthanvthe vdistance between the bars or 'rails used, and inthe 'sense' thatwhen rails of `a character best shown in1Fig.".2

are employed, the distance vbetween the upwardly deflected anges "7 isless than the distancebetween the heads `9 thereon-the ,y mesh ofthe'outermost'screening element, to

being the finest of `all.`

Itl may be understoodthat when bars` or wit, the wire' screenll; or itsequivalent,

rails of the character hereinv described are.

employed,both the materials fed to my millV andthe balls used thereinshouldbe small 115 decreasing in lthe sense that thediameter lol.

enough to permit their free movement in either an inward or outwardradial direction between the heads 9 of the mentioned eral characterdescribed,

rails or between the lateral edges 12 of the mentioned bars, therebypractically obviatin the risk of a permanent lodgement of bals ormaterials in a manner detrimental to the' efficiency of my mill.

In the operation of a mill of the gena mill may advanta eously beinitially filled practically half ful ofv balls, either of uniform or ofgraduated sizes, the interstices between the balls being initiallyoccupied by material to be ground, and balls and addltional materialbeing thereafter fed, preferably through one of the hollow trunnions, ata suicient rate and in a suitable ratio to substantially maintain thecondition initiall established; and it will be obvious that botii therompt elimination of suitably subdivided, material), by reason of theextensive exposition of the base screen employed, and the cascading ofballs from a comparatively high elevation, as may result from therotation of a 6 foot mill, or the like, at a rate of about twentyrevolutions, more or less,

per minute, may and do cooperate effectively in a rapid and economicalgrinding of ores or other materials.

Although I have herein described two advanta eous embodiments of myinvention, it will be understood that various features thereof might beindependently emplo ed and also that various additional modications'might be made by those skilled in the art without involving theslightest departure from the spirit and scope of my invention as thesame is indicated above and in the following claim.

What I claim is:

In a screening ball mill, a base screen forming a cylinder, railroadrails fitting against the inner face of the base screen and extendinglongitudinally, portions of the bases of the rails being riveted to thebase screen and the remaining portions of the bases being bent inwardlyaway from the base screen, and therails being so spaced apart that theballs will not pass between the rail bases,

In testimony whereof I have signed my name to this specification.

JOHN HERMAN.

